The invention relates to thermal printers, both in the context of printers which are peripherals of other equipment and apparatuses with integrated printer, such as, for example, facsimile machines.
More particularly, the invention relates to thermal printers in which a thermal printing head with resistive heating elements is provided for printing, on an a priori paper medium, pages of a document which is to be received from a calling party in the case of a facsimile machine. There are two main types of thermal printer.
In those of the first type, currently the most widespread, the medium is a special so-called thermal paper used in roll form.
In printers of the second type, which are starting to appear on the market, the medium is ordinary paper, then used in sheets or in reams, but which requires a special printing ribbon used in roll form. This is, more precisely, a ribbon coated with a layer of thermally meltable ink which, during printing, is transferred onto a sheet of the paper by activation of the heating elements of the head. In this case, printing by thermal transfer is spoken of.
With the former printers, there is the risk that the roll of thermal paper will end prematurely or unexpectedly.
With the latter printers, there is also the risk that the inking roll will end prematurely or unexpectedly.
Since the solution of providing two printers, respectively of the two types, is naturally to be set aside, the Applicant Company has sought to overcome the risk of the roll of thermal paper or inking ribbon running out, and it is in this context that it provides its invention.